Can you easily get a copy of the calls, made attempts and success, from your telco or mobile provider/mobile call logs? It may be useful to document with as much evidence as possible that you made attempts to contact BA about aspects of the booking which they should have recorded. If your documented recollection ties up with the recording it gives more credibility to your recollection of the conversations(ie check-in) that weren’t recorded. May possibly be useful to file as background info with MCOL although I doubt it will have great bearing on the case. Not sure what you asked for in SAR but the calls should be shown in there if you asked for all records regardless of date for the PNR. If they don’t it shows BA are not giving you the whole truth which is suspicious.